How this calculator works
Convert mixed numbers to improper fractions and decimals to exact base-ten fractions. Add each value using a common denominator, then reduce the running sum. In missing-addend mode, enter all known addends and subtract their sum from the known total. The table shows the running result for every entered value. Enter between two and fifty comma-separated values.
Formula
a/b + c/d = (ad + bc)/(bd). Missing addend = total - sum of known addends.
Worked example
1/2 + 1/3 = 5/6. Adding -1 1/2, 2/3 and 5/6 gives zero.
Advertisement
Frequently asked questions
How do I enter mixed numbers?
Write a space between the whole and fractional parts, such as -1 1/2. That minus sign applies to the entire number.
Do decimals lose precision?
No. A decimal such as 0.1 is interpreted as exactly 1/10. Repeating decimals must be entered as fractions for exact results.
How many values can I enter?
Enter 2 to 50 values separated by commas. Each value may contain up to 160 characters; empty items and zero denominators are invalid.